Weaving looms



Sept. 22, 1964 R. LAITHWAITE 3,149,648

,WEAVING LOOMS Original Filed Oct. 23, 1961 2 Sheets-Sheet 1 v INVENTOR:ERIC ROBERTS LAITHWAITE.

Sept. 22, 1964 E. 4R. LAITHWAITE WEAVING LOOMS 2 Sheets-Sheet 2 OriginalFiled Oct. 25, 1961 INVENTOR: ERIC ROBERTS LAITHWAITE.

United States Patent 3,149,648 WEAVING LOOMS Eric Roberts Laithwaite,Cheadle, England, assignor to National Research Development Corporation,London, England, a British corporation Original application Oct. 23,1961, Ser. No. 147,006. Divided and this application Feb. 25, 1963, Ser.No. 260,485 Claims priority, application Great Britain Oct. 27, 1960 3Claims. (Cl. 139-55) This application is divided from copendingapplication Serial No. 147,006 filed October 23, 1961.

The present invention relates to weaving looms and is more particularlyconcerned with improvements which enable a more constant tension to bemaintained in the warp threads during the weaving operation.

It is well known that the tension in the warp threads variesconsiderably in a conventional loom during the opening and closing ofthe shed. This variation in tension is very undesirable and it is theobject of the present invention to provide arrangements whereby thevariation in tension is substantially eliminated.

According to a feature of the invention, in a weaving loom havingarrangements for oppositely separating the warp threads to form a shed,the sley and the reed are maintained in a fixed position relative to theframe of the loom and cam-controlled means are effective to move thewarp threads and the cloth relative to the reed to effect the beat-upoperation, said cam-controlled means also being effective during theformation of the shed in ensuring that the tension in the warp threadsis substantially the same as it was prior to the shedding operation.

According to another feature of the invention, in a combined reed andhealds, the reed is maintained stationary with respect to the frame ofthe loom and consists of a plurality of members shaped to define a dentbetween any two of them and a plurality of sliding members each havingsupporting surfaces for a warp thread and each movably mounted withinone dent, means being provided for controlling the movement of thesliding members in the slots to form a shed.

The invention will be better understood from the following descriptionof a number of embodiments which should be taken in conjunction with theaccompanying drawings comprising FIGS. 1 to 6.

In the drawings;

FIG. 1 shows diagrammatically one embodiment for obtaining constant warpthread tension,

FIGS. 2 and 3 show diagrammatically another embodiment,

FIG. 4 shows a combined reed and healds,

FIGS. 5A, 5B and 5C show details of the sliding member forming thehealds, and

FIG. 6 shows the details of one of the plates forming the reed.

Referring first to FIG. 1, warp threads 61 and 62 are taken ofi a warpbeam 63 and passed through heald frames 64 and 65 and second healdframes 66 and 67 respectively. The warp threads 61 and 62 are held inrelatively fixed locations in the heald frames 64, 65 and 66, 67 inconventional manner and are free for vertical displacement in one or theother of the heald frames of each set. Upon leaving the second healdframes 66 and 67, the warp threads 61 and 62 pass through a reed 68 andacross the sley 69 to a take-up roller 70.

In operation, heald frames 66 and 67, reed 68, sley 69 and take-uproller 70 operate in a conventional manner, the raising and lowering ofthe heald frames 66, 67 being effected under the control of earns 71, 72mounted on the loom camshaft 73. The heald frames 64 and 65 aredisplaced at the same time as the heald frames 66 and 67 under thecontrol of cams 74, 75 also mounted on the loom camshaft 73. However,the displacement of the heald frames 64 and 65 is related to that ofheald frames 66 and 67 thereby causing a second separation of the warpthreads to maintain a uniform tension in each thread. Consider a singlewarp thread such as 61 extending from point A on the warp beam 63 to thecloth on point D of the sley 69, this thread passing through an eyeletin heald frame 64, freely through frame 65, through an eyelet in frame66 and freely through frame 67. A warp thread, such as 62, passes freelythrough the frame 64, through an eyelet in frame 65, freely through theframe 66 and through an eyelet in the frame 67. In the position shown inFIG. 1, both warp threads are tensioned and the heald frames are soarranged that the path AB+BC+CD followed by the thread 61 is equal tothe path AE-l-EF-i-FG +GD by the thread 62. During shed changing frames64 and 66 will be lowered and frames 65 and 67 will be raised so thatthread 62 will take up a position substantially that shown in FIG. 1 forthread 61 and vice versa. Further the path followed by the two threadsin the heald frames is such that during shed changing the distancebetween points A and D measured along the threads remains constant andhence the threads are under the same tension during shed changing.

The invention is not limited in its application to looms of conventionaltype but may be applied to looms where shed formation is not dependenton the provision of healds. Thus in the embodiment illustrated in FIGS.2 and 3, the shed is formed by cams 81 and 82, each Warp thread beingengaged by the periphery of one of said cams. The tension in the warpthread is maintained constant by passing the threads under an additionalpair of cams 83 and 84, each thread engaging the periphery of one ofsaid cams. The cams 81 and 82 are secured to the shaft and the cams 83and 84 to the shaft 86. The shafts 85 and 86 rotate at constant anduniform speeds and thereby the cam arrangement ensures that the threadsare of constant length between the points A and D for all positions ofthe cams 81 and 82 so that the tension in the threads is maintainedsubstantially uniform. FIGS. 2 and 3 show the positions of the two pairsof cams in the formation of different sheds, the path A B C D and thepath A B C D having the same length in the two drawings.

Referring now to FIGS. 4, 5 and 6, these show a combined reed andhealds. A short section of the combined reed and healds is shown in FIG.4 and consists of a plurality of similar members 200 each of which hasthe shape shown in FIG. 6. Referring to this drawing, each memberconsists of a fiat plate 201 having on one surface four equal raisedportions 202, 203, 204 and 205, one at each corner. When two such platesare mounted face-toface with the raised portions on one engaging theflat surface of the other as in FIG. 4, it will be seen that theseparation between the raised portions 202 and 204 and between 203 and205 defines a slot which forms one dent in the reed.

The healds are formed by a plurality of sliding members 206 (FIG. 4) oneof which is shown in detail in FIGS. 5A, 5B and 50. Each sliding memberconsists of a flat portion 207 having a cut-out which provides twoprojections 208, 209, the tips of which face one another and are spacedapart by substantially the same distance as the diameter of the aperturein the conventional wire healds. The flat potrion has two rearwardlyextending lips 210, 211 along each edge, the distance between the facingedges of the two lips being substantially equal to the width of theplate 201 (FIG. 6). In addition the thickness of the flat portion issubstantially equal to the height of the raised portions 202-205 (FIG.6). Operating members 212, 213 extend upwardly and downwardly of theflat portion and are each provided with lugs 214,

215, the lugs being provided on opposite sides of adjacent Slidingmembers as shown in FIG. 4. The sliding members 206 may be secured toheald frames, for instance, by means of wires passing through holes inthe lugs 214, 215 and in the arrangement shown in the drawing two healdframes would be used to give a plain weave. However, for patternweaving, the operating members may be controlled in the requiredcombinations byselector mechanism of known type.

I claim:

1. A combined reed and healds comprising a plurality of reed members,means securing said members together to define a plurality of dentsbetween adjacent pairs of said reed members, and a plurality of slidablemembers each having engaging surfaces for a warp thread, each of saidslidable members being movably mounted within one of said plurality ofdebts to form a shed.

2. A combined reed and healds as claimed in claim 1, wherein said reedmembers each comprise a flat plate having a projecting portion at eachcorner of one surface,

the height of the projecting portions being equal to the required widthof a dent.

3. A combined reed and heald as claimed in claim 2, wherein saidslidable members each comprise a body portion and top and bottom stemportions, the stem portions lying between the projecting portions at thetop and bottom of the associated reed member and the body portionincorporating the engaging surfaces and being flanged 12o engage withthe side edges of the associated reed mem- References Cited in the fileof this patent UNITED STATES PATENTS 521,656 Johanson June 19, 1894869,892 Gay Nov. 5, 1907 2,457,852 Tiefenthal Jan. 4, 1949 2,480,064Walker Aug. 23, 1949 FOREIGN PATENTS 1,436 Great Britain of 1901 760,419Great Britain Oct. 31, 1956

1. A COMBINED REED AND HEALDS COMPRISING A PLURALITY OF REED MEMBERS,MEANS SECURING SAID MEMBERS TOGETHER TO DEFINE A PLURALITY OF DENTSBETWEEN ADJACENT PAIRS OF SAID REED MEMBERS, AND A PLURALITY OF SLIDABLEMEMBERS EACH HAVING ENGAGING SURFACES FOR A WARP THREAD, EACH OF SAIDSLIDABLE MEMBERS BEING MOVABLY MOUNTED WITHIN ONE OF SAID PLURALITY OFDENTS TO FORM A SHED.